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A036091
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Centered cube numbers: (n+1)^13+n^13.
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4
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1, 8193, 1602515, 68703187, 1287811989, 14281397141, 109949704423, 646644824295, 3091621642217, 12541865828329, 44522712143931, 141515917523003, 409868311971325, 1096589879846397, 2739909841613519
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OFFSET
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0,2
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COMMENTS
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Never prime, as a(n) = (2n + 1) * (n^12 + 6n^11 + 36n^10 + 125n^9 + 295n^8 + 496n^7 + 610n^6 + 553n^5 + 367n^4 + 174n^3 + 56n^2 + 11n + 1). Semiprime for n in {1, 8, 15, 21, 86, 135, 141, 249, 260, 278, 323, 326, 363, ...}. - Jonathan Vos Post, Aug 26 2011
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LINKS
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MAPLE
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MATHEMATICA
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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